Memory cells of electronic memory devices such as dynamic random access memory typically employ a number of electronic components in order to save data. For instance, in order to store data, a combination of electronic components such as transistors, diodes, and/or capacitors are typically employed in such memory cells to store or not store electrical charges. If a charge is stored in such a memory cell, that may indicate a logic “1,” and if no charge is stored in such a memory cell that may indicate a logic “0.”
An alternative approach for storing data is to use memory cells made of phase change material (PCM). A PCM is a material that can be placed into at least two physical states, a crystalline state and an amorphous state, by increasing or decreasing temperature. By changing the physical state of the PCM, certain characteristics of the material, such as electrical resistance, may also change. Such properties may be exploited in order to form memory cells made of PCM (herein “PCM cells”).
Such memory cells are generally intricate and expensive to manufacture. Thus, it is important to manufacture them in such a way to ensure accuracy and reliability such that few memory cells are wasted. One concern involves the contact between a heater element and the PCM. Since it is undesirable to heat up the PCM, it is desirable to have a small contact between the PCM and the heater element. It is also desirable to have a high aspect ratio of a top contact on the PCM and to manufacture the cells in such a way that ensures quality but that is also efficient and economical.